The general methods for applying different colors and/or textures of coatings in such fashion that the colors remain distinctively separate after application include the application of each coating individually or the use of hydrophobic alkyd paints. Application of each coating individually is extremely labor-intensive. For industrial applications, the associated shutdown time often makes the use of multiple colors and/or textures of coatings cost-prohibitive. Further, when coatings are applied individually, each subsequent coat tends to dominate or obscure previous coats.
It might be thought that a use of several applicators would produce multiple colors of paint. Typical coating compositions and applicators such as coating guns, however, operate under conditions designed to deliver complete coverage. If several applicators are used simultaneously, the coating droplets tend to be so fine or atomized and so close together that the individual coatings will combine into a single, uniform coverage. There will be no color differentiation and the individual color/texture coatings will mix to form a composite color/texture. Thus, known plural component coating technology focuses on mixing a plurality of components either prior to or during the coating process. For example, U.S. Pat. No. 4,297,079, issued to Smith, discloses a plural component air coating gun that atomizes the two fluids into an atomized conical coat, thereby mixing the two liquid materials before they contact the surface to be coated. Such methods do not produce a multi-color surface generally.
Some attempts to produce multi-color surfaces have focused upon specially formulated multi-color coatings which are available as single coatings. In these paints, the droplets of each coating are agglomerated or encapsulated in soft breakable microcapsules. However, such agglomerated coatings are extremely expensive and have an extremely low solid to volume ratios, generally about 12.5% to 20%. Further, since the agglomerated microcapsules are designed to splatter when they hit the surface being coated, encapsulated coatings lack the strong binders needed to produce a durable surface that can stand up to solvents and harsh cleaners. Consequently, these coatings cannot be used for floors, exteriors, or industrial applications. One example of encapsulated paints is Zolatone.RTM..
Moreover, the agglomerated color microcapsules are generally very small, which limits the variability of texture or streak size. In order to force the color microcapsules through the coat system, agglomerated coatings must be coated at a high pressure, creating a wasteful fog of coating material. Finally, agglomerated coatings generally require a base color coat to achieve complete coverage of the surface.
Therefore, it is an object of the invention to develop a coating composition, apparatus and method for producing a multi-color and multi-effect surface. A further object is the development of a process for producing a multi-color and multi-effect surface in one coating application.